1. Field of Invention
This invention relates to an encoder of the absolute position type which outputs signals representing a shift position or an angle of rotation in relation to an absolute position; and more particularly, to such an encoder comprising a code plate having two sets of grid patterns and two sets of sensors facing the grid patterns, with the grid patterns containing information represented by "1" and "0" disposed periodically.
2. Description of the Prior Art
Rotary and linear encoders are known having a code plate wherein information is stored as "1" and "0" in the form of a grid pattern with a plurality of sensors to detect the grid pattern. The minimum measurable limit of measurement of shift position and angle of rotation is determined and limited by the extent to which the grid pattern can be miniaturized. Thus, accuracy and resolution at higher levels are limited.